The present invention relates to an imaging apparatus for visualizing a latent image formed on an image carrier by use of a developing device.
An imaging apparatus of the type described is well known in the art and constructed typically as a printer, facsimile apparatus and others. Also known in the art is an imaging apparatus of the kind having a body which consists of an upper part and a lower part, the upper part being openably supported by the lower part. In this kind of apparatus, an image carrier, developing unit and predetermined parts associated therewith are integrally mounted on a support member to constitute a single unit, and the single unit is detachably supported by the upper body part. In such a construction, when any of the parts included in the unit has failed, the unit may be bodily replaced with another by opening the body upper part away from the body lower part and, then, sliding the unit relative to the upper body part. This not only promotes the ease of maintenance of the apparatus but also makes it easy to remove jammed papers.
However, a problem with the prior art single unit scheme described above is that because the unit has to be replaced with the body upper part opened and held in an inclined position, the unit, too, has to be manipulated in an inclined position. This forces a person to hold himself or herself in an unnatural position throughout the maintenance work, resulting in limited operational efficiency. Another problem is that due to the sliding movement of the unit relative to the body upper part a jammed sheet is apt to be subjected to excessive forces to scratch the image carrier.
Moreover, even when only a single part in the unit, say the image carrier, has failed, the whole unit including even the developing device need be replaced, that is, even the parts in the unit which have not failed need be simply wasted.
Meanwhile, in the case where toners of different colors are selectively used, it is a common practice to prepare developing devices which are allocated one to each color of toner and selectively use the developing devices depending upon the desired color. Because the prior art single unit scheme cannot have the developing device to be replaced singly as stated above, the unit including the image carrier has to be bodily replaced every time a toner of one color is replaced with a one of another color. Hence, despite that provision of only the developing devices associated with respective colors suffices, bulky units each including an image carrier must be prepared requiring a considerable space for storage.